I. Field of the Invention
Embodiments of this invention are directed generally to biology and medicine. In certain aspects methods involve determining the prognosis for a breast cancer patient. In other embodiments, there are methods and compositions for treating a breast cancer patient with a glucocorticoid antagonist.
II. Background
There are over 1 million cases of breast cancer per year on a global basis, of which around 0.5 million are in the US, 40,000 are in the UK and nearly 2,000 in Ireland. It is the leading cause of cancer deaths among women (Keen and Davidson, 2003). Although the overall incidence of the disease is increasing within the western world, wider screening and improved treatments have led to a gradual decline in the fatality rate of about 1% per year since 1991. Inheritance of susceptibility genes, such as BRCA1 and BRCA2, account for only 5% of breast cancer cases and the factors responsible for the other 95% remain obscure (Grover and Martin, 2002). In the absence of a strategy to reduce causative agents of breast cancer, early detection remains the best approach to reducing the mortality rate of this disease. It is widely held that breast cancer initiates as the pre-malignant stage of atypical ductal hyperplasia (ADH), progresses into the pre-invasive stage of ductal carcinoma in situ (DCIS), and culminates in the potentially lethal stage of invasive ductal carcinoma (IDC). This linear model of breast cancer progression has been the rationale for the use of detection methods such as mammography in the hope of diagnosing and treating breast cancer at earlier clinical stages (Ma et al., 2003).
As more molecular information is being collated, diseases such as breast cancer are being sub-divided according to genetic signatures linked to patient outcome, providing valuable information for the clinician. Emerging novel technologies in molecular medicine have already demonstrated their power in discriminating between disease sub-types that are not recognizable by traditional pathological criteria (Sorlie et al., 2001) and in identifying specific genetic events involved in cancer progression (Srinivas et al., 2002).
Endocrine therapy is a popular mode of treatment for all stages of breast cancer. A majority of breast cancers belong to the type in which growth is stimulated by the female sex hormones, estrogens and progesterone. Therefore some of the therapies are based on depriving the tumor of the hormone-induced growth stimulus. Some of the current modes of endocrine treatments include blockade of the estrogen receptor with an antiestrogen, e.g. tamoxifen; hormonal ablation by surgery (oophorectomy, adrenalectomy or hypophysectomy), radiotherapy or medically by administration of a luteinizing hormone-releasing hormone analogue (LH-RHa), e.g., goserelin; suppression of estrogen synthesis with aromatase inhibitors, e.g., anastrozole; pharmacological doses of estrogens and progestagens, e.g., megestrol acetate.
Despite recent advances, the challenge of cancer treatment, including breast cancer therapy remains. Progress is limited with respect to the development of specific treatment regimens to clinically distinct tumor types, and to personalize tumor treatment in order to maximize outcome and efficiency. Moreover, a number of patients exhibit chemotherapy resistance.
Mere classification of breast cancers into a few subgroups characterized by low to absent gene expression of the estrogen receptor (ER) alone may not reflect the cellular and molecular heterogeneity of breast cancer, and may not allow the design of treatment strategies maximizing patient response. Once a patient is diagnosed with cancer, such as breast or ovarian cancer, or an individual wants predisposition analysis, there is a strong need for methods that allow the physician to predict the expected course of disease, including the likelihood of cancer recurrence, long-term survival of the patient, and the like, and accordingly select an appropriate treatment option that is effective.